We hear it’s full speed ahead for singer-songwriter Sara Bareilles, who is writing the score for a musical adaptation of the movie “Waitress” that American Repertory Theater artistic director Diane Paulus plans to direct. Paulus approached Bareilles (inset) for the project, and she started working closely with her on it last summer. Paulus describes Bareilles as “incredibly gifted” and notes that the pop artist is “really excited about writing for the musical theater.” Meanwhile Pulitzer winner Paula Vogel, who had initially been exploring ideas for the musical’s book with Paulus, was unable to continue with the project due to scheduling conflicts, according to the ART. A book writer will be announced at a later date.